微信小程序开发之异步转同步

onLoad: function(options) {

    //执行同步
    return new Promise(function (resolve, reject) {
      wx.checkSession({
        success: function (res) { resolve(res); },
        fail: function (res) {

          //同步代码好了，执行要执行的代码代码
          var that = this;
          wx.request({
            url: Util.exeCatalog(), //仅为示例，并非真实的接口地址
            data: {
              ParentId: 129,
            },
            method: ‘GET‘,
            header: {
              ‘content-type‘: ‘application/json‘ // 默认值
            },
            success(res) {
              var qa = res.data;//获取json数据

              var qaarr = [];//定义数组
              for (var i in qa) {

                var qacontentarr = [];//定义数组

                wx.request({
                  url: Util.exeContent(), //仅为示例，并非真实的接口地址
                  data: {
                    CatalogId: qa[i].CatalogId
                  },
                  method: ‘GET‘,
                  header: {
                    ‘content-type‘: ‘application/json‘ // 默认值
                  },
                  success(ress) {

                    qacontentarr = [];

                    var qacontent = ress.data;//获取json数据
                    for (var i in qacontent) {
                      var qaarrjson = {};
                      qaarrjson[‘zi‘] = qacontent[i].Title;
                      qaarrjson[‘li‘] = qacontent[i].Description;
                      qacontentarr.push(qaarrjson);
                    }

                  }
                })

                var qaarrjson = {};
                qaarrjson[‘id‘] = i;
                qaarrjson[‘hidden‘] = true;
                qaarrjson[‘title‘] = qa[i].CatalogName;
                qaarrjson[‘contentH‘] = qacontentarr;
                qaarrjson[‘image‘] = ‘/images/js.png‘;
                qaarr.push(qaarrjson);

              }

              that.setData({
                systemList: qaarr
              })

            }
          })

        }

      })
    })

  }

同步代码

onLoad: function(options) {

    //执行同步
    return new Promise(function (resolve, reject) {
      wx.checkSession({
        success: function (res) { resolve(res); },
        fail: function (res) {
             //执行的方法
        }
      })
    })    

}

原文地址：https://www.cnblogs.com/zpblogs/p/11323008.html